Striker Alan Lee will be out of action for three weeks after a scan showed a small tear to his hamstring. There is better news regarding defender Fabian Wilnis's rib injury.
Physio Dave Williams told the club site: "Alan has a small tear at the top of his hamstring.
"It could have been a lot worse but we are still looking at three weeks out."
Williams says Wilnis should be OK for the trip to Wolves: "Fabian was going to have an x-ray but the pain has eased considerably overnight so it's not necessary now.
"The ribs are bruised but he has a decent chance of being fit for the weekend."
Lee's absence is likely to see boss Joe Royle step up his loanee search.